That's why, unless you suspect something that is way out there in terms of remediation (and it sounds like you don't, given that you're looking to non-medication methods of coping/management), I'd try doing this as just individual learning needs first.
We've had individual teachers, lesson teachers, coaches, etc. be VERY cooperative with specific approaches that help integrate with the overall scaffold-- we just had to ask. We never couched any of this as "EF deficit" or anything-- just mentioned that "It helps {DD} when you remind her to write her practice schedule in her notebook."
(Previously the piano teacher even did if FOR her for a while-- then she asked if she wanted her to, and now she only very occasionally reminds.)
It's not that far out there to specifically teach EF to kids as adolescents. Most adults who work with kids this age are ready, willing, and able. Suggestions mostly will be well-received, we've found. This can be oral cues, timed reminders for larger projects, and similar things. Or asking about specific components of assignments, if that is problematic. Just touching a daydreaming/inattentive child on the shoulder gently in passing to redirect. That kind of thing.
You just have to figure out WHAT to suggest, and that is unique and based on the particular mosaic of skills in the child in question.
